This study will evaluate bright light use that would be cost-effective and practical for a large work area such as an emergency department. A comparison of the control period with that of the bright light period will be performed looking at four measures: 1) Temperature by tympanic membrance readings, 2) Sleepiness by the Stanford Sleepiness Scale, 3) Performance by an as yet to be determined test, and 4) Mood by an abbreviated symptom questionnaire type scale. CDMAS ONLY.